Dr. Duvall is one of the pioneers of helioseismology and has been
working in this area for more than twenty years. He is at least partly
responsible for a number of discoveries, including the relation commonly
known as Duvall's law, the initial measurements of rotation and sound
speed throughout much of the solar interior, and the asymmetry of solar
oscillation spectral lines. In recent years he helped invent the
technique known as time-distance helioseismology, in which travel times
are measured between different surface locations. This new technique
has lead to interesting results, including the first measurements of
meridional circulation in the solar interior and the measurement of flows
and sound speed inhomogeneities below sunspots.
Positions and Appointments
1977-1979 Kitt Peak National Observatory Position: Postdoctoral Fellow
1979-present Laboratory for Astronomy and Solar Physics NASA/Goddard Space Flight Center Position: Astrophysicist
Education
Johns Hopkins University B.A. 1972
Stanford University Ph.D.1978
Professional Services
NASA/NSO/Bartol Antarctic expeditions (1981-2, 1987, 1988, 1990, 1994-5)
NSO User's Committee, 1997-2000.
Cochair of the NASA Sun-Earth Connection Roadmap Team, 2002
Awards
NSF Antarctic Service Medal, 1982
NASA Exceptional Scientific Achievement Medal, 1990
Mount Duvall named by US Board on Geographic Names at 78S22,162E31, 1996
Publications
"On the Relationship between the Rotational Velocity and the
Field Strength of Solar Magnetic Elements", J. Zhao, A. G. Kosovichev,
and T. L. Duvall Jr., Ap. J. Letters, 607, L135-L138, 2004.
"Wave-like Properties of Solar Supergranulation",
L. Gizon, T.L. Duvall Jr., J. Schou, Nature 421, 43-44, 2003.
"A New Component of Solar Dynamics: North-South Diverging Flows Migrating
Toward the Equator with an 11-year Period",
J.G. Beck, L. Gizon, T.L. Duvall Jr., ApJL 575, L47-L50, 2002.
"Imaging an Emerging Active Region with Helioseismic Tomography",
J.M Jensen, T.L. Duvall Jr., B.H. Jacobsen, and J. Christensen-Dalsgaard,
ApJL 553, L193-L196, 2001.
"Time-Distance Helioseismology with f Modes as a Method for
Measurement of Near-Surface Flows", T.L. Duvall Jr. and L. Gizon,
Solar Physics 192, 177-191, 2000.
"Solar Tomography", A.G. Kosovichev and T.L. Duvall Jr.,
Current Science, 77, 1467-74, 1999.
"Long-lived Giant Cells Detected at the Solar Surface",
J.G. Beck, T.L. Duvall Jr., & P.H. Scherrer,
Nature, 394, 653-655, 1998.
"Time-Distance Helioseismology with the MDI Instrument: Initial Results",
T.L. Duvall Jr., A.G. Kosovichev, P.H. Scherrer, R.S. Bogart, R.I. Bush,
C. De Forest, J.T. Hoeksema, J. Schou, J.L.R. Saba, T.D. Tarbell,
A.M. Title, C.J. Wolfson, P.N. Milford, Solar Physics 170, 63-73, 1997.
